航空学报 > 1990, Vol. 11 Issue (8): 369-374

8090铝锂合金疲劳短裂纹扩展行为研究

陈铮   

  1. 西北工业大学
  • 收稿日期:1989-03-31 修回日期:1989-12-03 出版日期:1990-08-25 发布日期:1990-08-25

SHORT FATIGUE CRACK GROWTH BEHAVIOR IN 8090 ALUMINIUM-LITHIUM ALLOY

Chen Zheng   

  1. Northwestern Polytechnical University
  • Received:1989-03-31 Revised:1989-12-03 Online:1990-08-25 Published:1990-08-25

摘要: 研究了8090铝锂合金二维短裂纹的扩展行为,发现了短裂纹扩展抗力明显低于长裂纹,且随裂纹尺寸不同而异,其原因是裂纹闭合效应随裂纹尺寸变化。应用有效应力强度因子幅值可统一各种尺寸短裂纹乃至长裂纹的扩展行为。

关键词: 铝锂合金, 短裂纹, 裂纹闭合

Abstract: The fatigue crack growth rate of two-dimensional short cracks ( 2.2mm) and long cracks (Δa>6mm) were compared using CT type specimens in 8090 aluminium-lithium jalloys. It was found that the short cracks grew much faster than long cracks, and the applied stress intensity factor range for short cracks may-be much lower than the threshold for long cracks. The above differences are attributed to crack closure effects.The growth of physically short cracks can be rationalized with that for long cracks in terms of effective stress intensity factor range.

Key words: aluminium-lithium alloy, short crack, crack closure